Muhammad bin Ya’qub, from Muhammad bin Yahya, from al-Hasan bin Ali bin Abdillah, from Abdillah bin Jabalah, from Sayf, from Maymun al-Sayqal, from Abu Abdillah عليه السلام, who said: I said to Him عليه السلام: “A man experienced janabah (ritual impurity) during the night, so he performed ghusl, and in the morning he looked and saw janabah (impurity) on his clothing.” Imam عليه السلام said: "Praise be to Allah سبحانه وتعالى, who has not left anything without assigning a rule for it. If, when he stood for prayer, he looked and did not see anything, then there is no repetition (of prayer) required of him. But if, when he stood, he did not look, then he must repeat the prayer."